Preamble-Free Binary Polarization Shift Keying in Frequency Selective Channels

Spectrum sharing is enabled through different strategies at the physical and medium access layers, including reduction of the required average transmit energy per good bit. In this work, we propose a preamble-free communications technique that is feasible with coherent MIMO systems. At the transmitter, packets comprising multicarrier symbols with cyclic prefixes are transmitted, but without preambles typically required for channel estimation and carrier frequency offset estimation. At the receiver, classification methods are used to demodulate the signal without need for channel estimation. We illustrate the approach for a simple coherent MIMO technique, binary PolSK, and demonstrate its efficacy by demodulating preamble-free packets transmitted in over-the-air experiments in multi-path channels.